Cholecystokinin (CCK) is a neuropeptide composed of thirty three aminoacids. See: Mutt and Jorpes, Biochem. J. 125 678 (1971). CCK exists in both gastrointestinal tissue and the central nervous system. CCK is believed to play an important role in appetite regulation and CCK may be a physiological satiety hormone. CCK reportedly co-exists with dopamine in certain mid-brain neurons and thus may additionally play a role in the functioning of dopaminergic systems in the brain, as well as, serving as a neurotransmitter in its own right. See: A. J. Prange et al., "Peptides in the Central Nervous System", Ann. Repts. Med Chem. 17 31, 33 (1982) and references cited therein, J. A. Williams, Biomed. Res. 3 107 (1982) and J. E. Morley, Life Sci. 30 479 (1982). CCK antagonists are useful in the treatment and prevention of disorders of the gastrointestinal, central nervous and appetite regulatory systems of animals, especially humans.